“…Sumac contains polyphenols, gallic acid, anthocyanins, hydrolysable tannins, tannic acid, ellagic acid, catechin, essential oils, gallotannins, and malic acids, which show antioxidant and antimicrobial effects (Hajib, ). Chitosan also has antimicrobial activity both‐gram positive and gram‐negative bacteria (Chaparro‐Hernandez et al, ; Gerasimenko, Avdienko, Bannikova, Zueva, & Varlamov, ; Vatavali, Karakosta, Nathanailides, Georgantelis, & Kontominas, ; Yuan et al, ). Chitosan combined with sumac acted as an antimicrobial, antioxidant agent so inhibited the growth of bacteria and extended the microbiological shelf life of rainbow trout fillets.…”